There’s a certain rarified echelon of video games that have birthed entire genres based on their innovation, and their fingerprints can still be spotted all over many games today. Super Mario Bros. defined the concept of a side-scrolling platformer, DOTA made the MOBA mainstream, and Doom is the benchmark for first-person shooters. There’s no way that the likes of Halo, The Last of Us, or The Day Before would exist without the sick, twisted fantasies of iD Software’s developers in the early ‘90s. By today’s standards, 1993’s Doom seems like a simple game. As a space marine sent to Mars,...